1. A business or commercial operation that operates in violation of laws and regulations, without proper licensing or authorization
The authorities shut down the illegal enterprise that was operating from the warehouse.
As autoridades fecharam a empresa ilegal que operava a partir do armazém.
2. An unlicensed or unregistered commercial activity conducted outside the legal framework
He was arrested for running an illegal business without the required permits.
Ele foi preso por dirigir uma empresa ilegal sem as licenças necessárias.